Abstract: A device for visual positioning of the type including a fixed scale (2), arranged on a base (1), defining an axis (Y), for pointing at a first landmark (5), at least two moving scales (6, 7), generating the axes (X, Z), concurrent with the axis (Y), for pointing at other landmarks (10, 13), jointed about an assembly piece (22), fixed to the base (1), provided with a hole (14) in the centre thereof, at least one steerable plate (15) or a steerable prism on a pivot, inserted in a fixed manner into said hole (14). The plate (15) or the prism permits a simultaneous direct sighting of the first landmark (5) and a reflected sighting of at least one of the other landmarks (10, 13). The invention is characterised in including elements for facilitating and speeding up the positioning of the axes (X, Y, Z), following or simultaneous to the orientation of the plate (15) or prism.

Abstract: A device for producing thrust from a flow of accelerated fluid, including: a fluid accelerator (1) fitted with drive vanes (5) and rotated inside a stator (10) about an axis of revolution; a circularly symmetrical stationary web portion (7) centered on the axis and having a plurality of fins (8) shaped to rectify the trajectory of fluid coming from the accelerator in order to form a hollow jet (9) with a volume of space within the hollow jet; and ducts (17) for supplying pressure to the volume of space within the hollow jet (9). The invention relates to an improvement where drive members (12) for the accelerator (1) are disposed in the volume of space within the hollow jet (9).

Abstract: A hydraulic jet propelling apparatus has an inlet opening at one end and an outlet opening at the opposite end for a fluid passing therethrough. Between the inlet and outlet openings, a centrifugal accelerator member defines a divergent annular passageway for the fluid, with a frusto-conical external sleeve and a frusto-conical central vaned rotor member keyed together on a driving shaft. A stationary cup shaped wall projects from an outlet of the accelerator member, an internal face of which, seen in axial section, having a curvature variable from the outlet of the accelerator member to define at an outer end thereof a straight direction substantially axial to said internal face. The internal face being provided with a plurality of vanes for guiding and progressively changing direction of the accelerated fluid from a diverging and rotative trajectory when leaving the accelerator member to a trajectory parallel to the straight direction when leaving the wall.